Method and apparatus for arbitrating one or more media streams within a single PoC session

ABSTRACT

A method of managing a Push-To-Talk over Cellular communication session includes establishing, with a first user equipment, a Session Initiation Protocol Push-To-Talk session that includes a Session Initiation Protocol Push-To-Talk server and at least one second user equipment. The method also includes designating, with the first user equipment, either the Session Initiation Protocol Push-To-Talk server or one of the at least one second user equipment, to act as an arbiter of a media stream. The method further includes transmitting, with the first user equipment, while engaged in the Session Initiation Protocol Push-To-Talk session, the media stream directly to at least one of the at least one second user equipment without receiving a transmit instruction from the Push-To-Talk server.

FIELD OF THE INVENTION

The present invention generally relates to the field of wirelessmultimedia communications, and more particularly relates toindependently arbitrated multimedia content transmission within amulti-user communication session.

BACKGROUND OF THE INVENTION

In a Push to Talk (PTT) communication session, a user with acommunications device pushes a “Talk” button to transmit voice or othermedia to one or more other devices participating in the PTTcommunications session. Each user is able to initiate a transmission ifno other communications device is transmitting/speaking, therebysupporting a communications session involving multiple users where eachuser is able to participate. Cellular telephone systems areincorporating functionality to perform PTT over Cellular (PoC)communication sessions, whereby a user is able to operate a cellularphone in a manner that appears to the user to be a conventional PTTcommunications session.

PoC communication sessions are sometimes managed by transmission ofSession Description Protocol (SDP) and Session Initiation Protocol (SIP)messages between a PoC controller, in conjunction with a Radio AccessNetwork (RAN), and multiple Mobile Subscriber (MS) units.

A standard known as OMA PoC 1.0 (http://www.openmobilealliance.org)focuses primarily on voice services for 1-to-1, group, and chat roomcall types. As broadband technologies become more prevalent, thesesimple call types will evolve. Users will desire to share multiple mediastreams (e.g., voice, music, and video) within the confines of a singlePoC session. However, whenever multiple media streams are present, theissue of floor control arises.

In PoC 1.0, floor control for voice is carried out by the TalkburstControl Protocol (TBCP), which is used by the PoC server. The PoC serveris a central arbiter and the floor is granted to a single client at atime. Because the voice stream is arbitrated only by the controlling PoCserver, the system suffers from the disadvantage that originatingclients cannot select how each stream is arbitrated.

Situations can arise where a client may wish to designate one stream inthe session to be arbitrated by the controlling PoC server and anotherstream arbitrated by one of the clients in the session. For instance, aPoC user participating in a group call, in addition to hearing the audioof the current talker, may wish to select the video feed of anothergroup member (who may not be the current talker). Unfortunately, currentPoC server arbitration management methods do not support multiple mediastreams in a single session with independent floor arbitration controlfor each media stream.

In some communication sessions, certain content is essential for thepurpose of the session. For instance, if a session is for discussing aparticular piece of video, it is useless to include a user with a devicethat is not capable of displaying the video. In other cases, content isan enhancement to the conversation, but not necessary. With current PoCsystems, originating clients cannot designate which of multiple mediastreams in the session are mandatory (i.e., all participants mustreceive) or optional (terminating clients may select the streams theywish to receive).

Additionally, there is no currently existing method for a user in asession to electronically request another user in the same session toinitiate a subsequent media stream to the current session (e.g., user 1requests user 2 to begin transmitting video).

Therefore a need exists to overcome the problems with the prior art asdiscussed above.

SUMMARY OF THE INVENTION

Briefly, in accordance with one aspect of the present invention a methodof managing a Push-To-Talk over Cellular communication session includesestablishing, with a first user equipment, a Session Initiation ProtocolPush-To-Talk session that includes a Session Initiation ProtocolPush-To-Talk server and at least one second user equipment. The methodalso includes designating, with the first user equipment, either theSession Initiation Protocol Push-To-Talk server or one of the at leastone second user equipment to act as an arbiter of a media stream. Themethod further includes transmitting, with the first user equipment,while engaged in the Session Initiation Protocol Push-To-Talk session,the media stream directly to at least one of the at least one seconduser equipment without receiving a transmit instruction from thePush-To-Talk server.

In accordance with another feature of the present invention, thetransmitting is in response to a floor grant from at least one of the atleast one second user equipment.

In accordance with yet another feature, the present invention includesreceiving, by the first user equipment, while engaged in the SessionInitiation Protocol Push-To-Talk session, the media stream directly fromat least one of the at least one second user equipment.

In accordance with a further feature, the present invention includesdesignating the media stream as mandatory and sending an instruction toremove from the session all of the second user equipment that do nothave media playback ability.

In accordance with still another feature, the present invention includesdesignating the media stream as optional.

In accordance with still another feature, the present invention includesrequesting from one of the at least one second user equipmenttransmission of a media stream.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying figures where like reference numerals refer toidentical or functionally similar elements throughout the separate viewsand which together with the detailed description below are incorporatedin and form part of the specification, serve to further illustratevarious embodiments and to explain various principles and advantages allin accordance with the present invention.

FIG. 1 is a system diagram for a multi-party wireless communicationsystem according to an embodiment of the present invention.

FIG. 2 is a Push-To-Talk over Cellular (PoC) infrastructure system blockdiagram according to an embodiment of the present invention.

FIG. 3 is a mobile subscriber unit block diagram according to anembodiment of the present invention.

FIG. 4 is a block system diagram of a Push-To-Talk (PTT) communicationssession where a Push-To-Talk over Cellular (PoC) server is incommunication with multiple users equipment according to an embodimentof the present invention.

FIG. 5 is a Push-To-Talk (PTT) communications session processing flowdiagram where a receiving user equipment acts as arbiter of a media fileaccording to an embodiment of the present invention.

FIG. 6 is a Push-To-Talk (PTT) communications session processing flowdiagram with a media file and at least one user equipment that is notcapable of viewing video according to another embodiment of the presentinvention.

FIG. 7 is a Push-To-Talk (PTT) communications session detailedprocessing flow diagram according to another embodiment of the presentinvention.

DETAILED DESCRIPTION

As required, detailed embodiments of the present invention are disclosedherein; however, it is to be understood that the disclosed embodimentsare merely exemplary of the invention, which can be embodied in variousforms. Therefore, specific structural and functional details disclosedherein are not to be interpreted as limiting, but merely as illustrativeexamples for the claims and as a representative basis for teaching oneskilled in the art to variously employ the present invention invirtually any appropriately detailed structure. Further, the terms andphrases used herein are not intended to be limiting; but rather, toprovide an understandable description of embodiments of the invention.

The terms “a” or “an”, as used herein, are defined as one or more thanone. The term plurality, as used herein, is defined as two or more thantwo. The term another, as used herein, is defined as at least a secondor more. The terms including and/or having, as used herein, are definedas comprising (i.e., open language). The term coupled, as used herein,is defined as connected, although not necessarily directly, and notnecessarily mechanically.

The present invention, according to an embodiment, overcomes problemswith the prior art by providing a system and method that providesmultiple independently arbitrated media streams within a single PoCsession.

User equipment incorporating an embodiment of the present invention areable to exchange multiple media streams in a single SIP session, withthe source of each media stream having the ability of being independentfrom the other sources. In addition, each stream may have a differentarbiter, with the initiating PoC client requesting the arbiter for eachmedia stream in the PoC session.

FIG. 1 is a system diagram of an exemplary multi-party wirelesscommunication system 100 according to an embodiment of the presentinvention. The multi-party wireless communications system 100 supports,for example, Push-To-Talk (PTT) over Cellular (PoC) communicationsbetween and/or among two or more instances of users equipment (UEs),such as mobile stations (MSs) 106-108, for example, a cellulartelephone, a radio telephone, a smart phone, or a wireless-enabledpersonal computer, laptop computer, or personal digital assistant (PDA).MSs 106-108 of the exemplary embodiment are in wireless communicationwith a radio access network (RAN) 104. The invention, however is notlimited to wireless user communication devices and a user equipment (UE)as referred to herein, can include any other user communication device,such as a wired communication device 112, for example, an Ethernetconnected UE such as a personal computer or a laptop computer.

RAN 104 includes a transceiver 102, such as a base transceiver station(BTS) or a Node B, coupled to a controller 103, such as a base stationcontroller (BSC) or a radio network controller (RNC). RAN 104 providesRadio Frequency (RF) services to MSs 106-108 residing in a coverage areaof the RAN. The exemplary embodiments of the present invention utilizecellular radio communications techniques to support communicationsbetween MSs 106-108 and RAN 104. Communications sessions including anMS, such as one of MSs 106-108, are able to include PoC communicationswith other MSs 106-108 or other suitably equipped users equipment inconnection with the RAN 104, through either wireless or wiredcommunications links.

PoC communications are controlled in the exemplary embodiment by a PoCcontroller 110 that is in communication with the RAN 104. Althoughdepicted in FIG. 1 as a single element, in various embodiments of thepresent invention PoC controller 110 may comprise multiple processorsthat are distributed across a cellular communications infrastructure toprovide efficient processing of PoC communications sessions across acellular telephone network. The PoC controller 110 is also connected to,for example, wired communications devices 112 through a suitable wiredinterface. Together, RAN 104 and PoC controller 110 are collectivelyreferred to herein as a network of communication system 100.

The PoC controller 110 establishes and maintains PoC sessions with UEsthrough data messages that conform to modifications of messages definedby the Session Description Protocol (SDP), Session Initiation Protocol(SIP), and Talk Burst Control Protocol (TBCP). The SDP is defined by RFC2327 and the SIP is defined by RFC 3261, both produced by the InternetEngineering Task Force, and the TBCP is defined within theOMA-TS_PoC-UserPlane-V1_(—)0-20060127-C, produced by the Open MobileAlliance. The content and teachings of all of these protocol definitionsis hereby incorporated herein by reference and the modifications tothese protocol standards are described below. The exemplary embodimentsof the present invention utilize these modified protocols to moreefficiently manage PoC communications sessions.

The exemplary multi-party wireless communication system 100 supportscommunications among UEs, for example, between an MS, such as MS 106,and other MSs 107, 108 or wired communications device 112, through theprocessing provided by the RAN 104, the PoC controller 110, and othercontrollers (not shown) that are associated with the multi-partywireless communication system 100, as would be understood by ordinarypractitioners in the relevant arts in light of the present discussion.Further embodiments of the present invention are able to use anysuitable wired or wireless communications link to connect the MSs106-108 to the PoC controller 110, such as Bluetooth® links, infraredlinks, or any suitable digital or analog link. Once a communication linkis set up between any two or more of the UEs, the PoC controller 110carries out floor control by using the Talkburst Control Protocol(TBCP). In this mode, the PoC server 110 can serve as a central arbiterfor voice communication. However, in other embodiments of the presentinvention, as will be explained in detail below, any of the UEs, such asMSs 106-108 or wired communication device 112, are able to serve asarbiters of any of a plurality of available media streams that may becommunicated during any single session.

An arbiter of a media stream, such as a voice communication, incommunication system 100 controls a grant of a floor with respect tosuch a media stream, for example, by conveying a floor grant, that is,an instruction to transmit, to a party that the arbiter determines hasthe floor, and further may determine which participants in a PoCcommunication session may or may not receive the media stream. Thearbiter may grant a floor in response to receiving a media stream (forexample, granting the floor to itself), or the arbiter may grant a floorto a UE in response to receiving a request to transmit from the UE. Invarious embodiments of the present invention, the transmit request mayidentify the media for which a grant is requested or the media sought tobe transmitted may be evident to the arbiter, for example, when PoCcontroller 110 or a UE is an arbiter for only one of the multiple mediastreams. When a UE receives a floor grant, the UE may then transmit theassociated media stream.

FIG. 2 is a PoC infrastructure system block diagram 200 according to anembodiment of the present invention. The exemplary PoC infrastructuresystem block diagram 200 shows details of the RAN 104 and the PoCcontroller 110. The RAN 104 includes RF circuits 202 and basebandprocessing 204 to implement cellular radio communications between an MS,such as MS 106, and one or more other MSs 107, 108 and/or othercommunications devices, such as wired communications device 112. RFcircuits 202 reside in transceiver 102 and baseband processing 204 mayreside in transceiver 102 or controller 103 or may be distributed amongthe transceiver and the controller.

The PoC controller 110 includes a time keeper 208 that tracks varioustime periods defined by the communications protocols implemented by thePoC controller 110, and triggers processing after expiration of thosespecified time periods. The PoC controller 110 further includes aprocessor 210, such as one or more microprocessors, microcontrollers,digital signal processors (DSPs), combinations thereof or such otherdevices known to those having ordinary skill in the art, that executesprograms and provides control to various devices within and associatedwith the PoC controller 110. The processor 210 creates and dispatchesmessages defined by the various protocols implemented by the PoCcontroller 110 for transmission by the RAN 104 to the MSs 106-108. Theprocessor 210 also processes protocol messages received from the MSs106-108 through the RAN 104. For example, the processor 210 generatesand processes received SDP, SIP and TBCP messages. The PoC Controller110 further includes a memory 212 that stores data and programs that areaccessed and manipulated by the processor 210.

The operation of the processor 210, and the PoC controller 110 ingeneral, is controlled by computer programs stored in a program memory220 within memory 212. The program memory 220 of the exemplaryembodiment includes a PTT call control program 224. The PTT call controlprogram 224 implements the protocol processing for the SDP, SIP, TBCP,and other protocols implemented and controlled by the PoC controller110.

The memory 212 further includes a volatile memory 222. The volatilememory 222 of the exemplary embodiment stores information beingprocessed by the processor 210. For example, the volatile memory 222stores communications session data 230, which contains data specifyingPoC communications sessions being controlled by the PoC controller 110.

FIG. 3 is a block diagram of a UE 300, such as MSs 106-108 and wiredcommunication device 112, according to an embodiment of the presentinvention. The UE 300 includes a transceiver 302 for interfacing withthe communications system 100 network and other UEs and for receivingcommunications from, and conveying communications to, another UEdirectly or via the network. In the event that the UE 300 is a wirelesscommunication device, such as MSs 106-108, transceiver 302 may includeRF circuits 304 that are used to perform radio communications with, forexample, the RAN 104, and in particular transceiver 102, via an antenna.The UE 300 further includes baseband circuits 306 that process basebanddata, such as voice signals or user data, which are received ortransmitted by the transceiver 304. The UE 300 further includes amicrophone 310 and a speaker 308 to support voice communications.Baseband circuits 306 of the exemplary embodiment are further able toreceive and decode protocol data messages and user data, which areexchanged with a processor 314 described below.

The operation of the UE 300 is controlled by a processor 314, such asone or more microprocessors, microcontrollers, digital signal processors(DSPs), combinations thereof or such other devices known to those havingordinary skill in the art. The processor 314 executes computer programsstored in a main memory 322 and a volatile memory 320 that are coupledto, or included in, the processor 314 and manipulates and accesses datastored in the main memory and the volatile memory. The main memory 322includes programs that make up a communications sessions controller,including a communications session processing program, a communicationssession messaging control program, and a communications sessionmaintenance processing program. In addition, the main memory 322 has adata storage area 330 for storing data such as video, audio, pictures,graphics and others. Data stored and manipulated in the volatile memoryincludes, for example, communications session data 324, which definesdata concerning established communications sessions to which the UE 300is assigned.

The processor 314 controls the operation of the UE 300 while operatingin a PoC communications session. While in a PoC communications session,UE 300 generally receives voice and/or data transmissions that originatefrom other users and originates voice and/or data transmissions. A userof the UE 300 is able to transmit signals, such as voice signals pickedup by microphone 310, by pressing a PTT button 312 in communication withthe processor. Pressing the PTT button 312 is detected by the processor314, and protocol messages to configure the PoC communications sessionto allow the UE to transmit are exchanged through the baseband circuits306 and RF circuits 304 of the MS. A user of the UE 300 is also able tocapture video via a camera 332 coupled to the base band circuits 306.Video captured by the camera 332 can be transmitted to other UEs, suchas MSs 106. In addition, video captured by the camera 332 can be storedin main memory 322 and recalled at a later time for transmission. Soundcaptured by microphone 310 can also be stored in main memory 322 andrecalled at a later time for transmission to other UEs.

The embodiments of the present invention preferably are implementedwithin the PoC controller 110 and the UE 300, and more particularly withor in software programs and instructions stored in the respectivememories 212, 320, 322, of the PoC controller and the UE and executed bythe respective processors of the PoC controller and the UE. However, oneof ordinary skill in the art realizes that the embodiments of thepresent invention alternatively may be implemented in hardware, forexample, integrated circuits (ICs), application specific integratedcircuits (ASICs), and the like, such as ASICs implemented in one or moreof the of the PoC controller and the UE. Based on the presentdisclosure, one skilled in the art will be readily capable of producingand implementing such software and/or hardware without undoexperimentation.

FIG. 4 is a block diagram illustrating a SIP PTT communication sessioninvolving a PoC server, for example, PoC server 110, and multipleparticipants, or UEs, for example, MSs 106-108, according to variousembodiments of the present invention. In the embodiments depicted inFIG. 4, the PoC server 110 retains control (arbitration), that is,serves as arbiter, of the voice communication function of the SIP PTTcommunication session. The arbiter determines which voice or data istransmitted to whom and at what time. The PoC server may be designatedas the arbiter by a UE, such as MS 106, that originated thecommunication session or may retain control of the voice communicationfunction by default. As is shown in FIG. 4, the PoC server 110, servingas the voice arbiter for the session, receives voice data from a firstUE of the multiple UEs, for example, MS 106, and retransmits it to otherUEs of the multiple UEs, for example, to a second UE of the multipleUEs, for example, MS 107, and a third UE of the multiple UEs, forexample, MS 108.

In one embodiment of the present invention, when a user, such as a userof MS 106, initiates a video-enabled SIP PTT communication session,instead of simply transmitting the current talker's video to everyparticipant, the initiating user could be provided with a choice. Insuch an embodiment, the PoC server 110 allows a sharing amongst the UEsparticipating in the communication session, such as MSs 106-108, ofarbitration of particular aspects of the communication session and ofparticipation in the communication session. That is, while the PoCserver 110 retains control of the voice communication function of thecommunication session, the PoC server may allow multiple media streamsto be exchanged in the session wherein the source for each media streammay be independent (e.g., video may be originated by a UE different fromthe originator of the session and/or different from the current talker)and the arbiter of each media stream may be different. For example, whenthe communication session includes multiple media streams, theoriginator of the session may designate an arbiter for each stream ofthe multiple streams or an originator or a sender of each stream maydesignate an arbiter for that stream. That is, an originator or sender(which sender may receive the media stream from another sender) of afirst stream of the multiple media streams may designate an arbiter ofthe first stream and an originator or sender of a second stream of themultiple media streams may designate an arbiter of the second stream,which designated arbiters may be different from each other and/or maycomprise one or more of the PoC server, the designating originator orsender, or a UE other than the designating originator or sender.

For example, FIG. 5 is a logic flow diagram 500 of a PTT communicationssession where a receiving UE acts as arbiter of a media file inaccordance with an embodiment of the present invention. Referring now toFIGS. 4 and 5, a SIP PTT communication session is originated by a firstUE, that is, MS 106. At step 502, a second UE, for example, MS 107,participating in the communication session originates a first videostream, video1, begins acting as an arbiter of the first video stream,and conveys the first video stream to a third UE, for example, MS 108,participating in the communication session without receiving a transmitinstruction from the PoC server 110. At step 504, in response toreceiving the first video stream, the third UE, that is, MS 108, maybegin acting as an arbiter of the first video stream. At step 506, thethird UE retransmits the first video stream to one or more other UEs,for example, to the first UE, that is, MS 106, without notifying, orreceiving a transmit instruction from, the PoC server 110. The first UEthen may begin acting as an arbiter of the first media stream.Similarly, at step 508, the third UE, that is, MS 108, originates asecond video stream, video2, begins acting as an arbiter of the secondvideo stream, and sends the second video stream to one or more otherUEs, for example, to the second UE, that is, MS 107. At step 510, thesecond UE may begin acting as an arbiter of the second video stream,again without notifying, or receiving a transmit instruction from, thePoC server 110. Processing flow diagram 500 then ends.

In one embodiment of the present invention as illustrated in FIG. 5,each sender of a media stream is able to designate, either before,during, or after transmission, a particular arbiter for a video stream,or file (e.g., a push-to-show application). In turn, when acting as anarbiter of a media stream, the UE controls a grant of a floor withrespect to such a media stream, for example, by conveying a floor grant,that is, an instruction to transmit, to a party that the arbiterdetermines has the floor, and further may determine which participantsin a PoC communication session may or may not receive the media stream.The arbiter may grant a floor in response to receiving a media stream(for example, granting the floor to itself without receiving adesignation from another arbiter, and then sending the stream withoutrequesting permission to do so), or the arbiter may grant a floor to aUE in response to receiving a request to transmit from the UE.Furthermore, when acting as an arbiter of the media stream, a UE mayreplicate the media stream to produce multiple replicated copies of themedia stream and then convey the multiple replicated copies to multipleother participants in the communication session.

For example, the user of the UE initiating the session can request, thatis, designate, an independent arbiter for each stream in the session orcan request all streams to have a single arbiter (“shared arbitration”).By way of another example, a participating UE may submit a request thata media stream be added to a communication session by itself or byanother session participant after the session has begun (e.g., one usercan request another user to add video to the current voice session) andconcurrent with, or after, conveying the request, designate an arbiterof that stream, for example, itself or another recipient of that stream.

For example, a SIP PTT communication session typically is set up by anoriginator, such as one of MSs 106-108, conveying a session invention,such as a SIP INVITE, to a PoC server, such as PoC server 110. Thesession invitation identifies a group and/or target UEs that are invitedto participate in the call. In response to receiving the sessioninvitation, the PoC server then conveys session invitations, such as SIPINVITEs, to the target UEs. In an embodiment of the present invention,the originator and PoC server may convey session invitations thatinclude data fields that identify an arbiter of a media flow, such asSIP INVITES that are modified to include such data fields, for example,by modifying SDP (Session Description Protocol) parameters. Afterarbiters are designated, a designated arbiter of a media flow maydesignate a new arbiter of the flow by indicating the new arbiter in amodified version of a SIP REINVITE or a modified version of a SIP UPDATEthat is sent by the current arbiter to the other participants in thesession, which messages are modified to include a data field identifyingthe new arbiter, again, for example, by modifying SDP parameters.

In another embodiment of the present invention, in response toconveying, to a designated arbiter, a request to transmit and receivinga floor grant in return, a participating UE may replicate the mediastream to produce multiple replicated copies of the media stream andthen convey the multiple replicated copies to multiple otherparticipants in the communication session. For example, with respect toFIG. 5, any of the participating UEs, that is, MSs 106-108, instead ofacting as an arbiter of a received video stream, may instead convey arequest to transmit to an acting arbiter, such as the UE that conveyedthe stream to the receiving UE. In response to receiving a floor grant,the UE may replicate the media stream to produce multiple replicatedcopies of the media stream and then convey the multiple replicatedcopies to other participants in the communication session.

In yet another embodiment of the present invention, users participatingin a group call can be provided with a list of all participants whosevideo the user could view. A user could then select whicheverparticipant he/she desires to receive video from and so inform thenetwork, and the network could transmit the video of the selectedparticipant to that user. The present invention provides completeflexibility; instead of just viewing the current talker, the users couldpick whose video they can and wish to receive.

Most devices allow each individual user to disable/enable his/her videotransmission and reception abilities. In one embodiment, a list ofvideo-enabled participants, that is, those participants whose UE arevideo enabled, is made available to a transmitting user. Thetransmitting user can then take into account the enabled/disabled statusof other users participating in the session before including aparticipant in the list of users who will participate in the videoaspect of the session.

For example, FIG. 6 is a processing flow diagram 600 of a PTTcommunications session with a media file and at least one UE that is notcapable of viewing video according to another embodiment of the presentinvention. Referring now to FIGS. 4 and 6, suppose, at step 602, thesecond UE, that is, MS 107, starts a one-to-many PoC call with the firstand third UEs, that is, MSs 106 and 108. Now assume the user operatingthe first UE, that is, MS 106, has video transmission from his/her UEdisabled and has so informed the network. At step 604, the second UE,that is, MS 107, as the originator of the session, is granted the floorto talk and enables video on his/her device for the call. At step 606, alist identifying the third UE, that is, MS 108, is provided to thesecond UE by the network. The first UE, that is, MS 106, is not includedin the list since the first UE disabled video transmission. In a callwith more users, a list identifying all users with video enabled wouldbe delivered by the network to all other users in the call with videoenabled. This also applies to audio enablement/disablement.

At step 608, the user operating the third UE, that is, MS 108, can electto watch the second UE's video. Similarly, at step 610, the useroperating the second UE, that is, MS 107, can elect to watch a mediafile sent from the third UE, that is, MS 108. Processing flow diagram600 then ends. In other words, any participating user with video enabledcan elect to receive video from any other user participating in the callthat has video enabled. The user operating the first UE may opt-out ofreceiving video but may continue to receive audio. If the video mediafile, or stream, is set to “mandatory” status, then the first UE, thatis, MS 106, may be excluded from the session. Thus, communication system100 may provide true flexibility as to whose video each participant in agroup call receives.

Because clients are able to select which streams of the session theywish to receive, in one embodiment of the present invention, the sessionoriginator is able to designate one or more media streams of multiplemedia streams as “mandatory” (all session participants are requested toreceive the stream) or “optional” (potential receiving clients can electto block the stream). In various embodiments of the present invention,with respect to mandatory media streams, an arbiter and/or a sending UEcan send an instruction to participating users equipment, or to the PoCserver, to remove from the entire communication session all of thecommunication devices that do not have media playback ability withrespect to the mandatory media stream, to disallow the sessionaltogether if any of the participating UE does not have media playbackability with respect to the mandatory media stream, or to disallow anyUE that does not have media playback ability from receiving themandatory media stream. With respect to optional media streams, UEs thathave media playback ability for the optional media stream may choosewhether to receive and/or display the media stream. For 1-to-1 sessions,the originator could also have the ability to specify if the videostream is full-duplex or simplex.

The above-described features of the present invention provide a powerfuland general capability which enables many new PoC/PTT services for1-to-1, group, and chat sessions. These services include:

-   -   Push-to-Show with arbitrated video, where one user may be        talking while another user in the same session is sharing video.        Only one video stream is active in this type of session. In this        particular service, both the voice and video streams are        mandatory and arbitrated by the PoC server.    -   Push-to-Show with non-arbitrated video, where one user talks at        a time but all users can independently request video from other        users in the same session. Video and audio streams can be        synchronized. In this service, the voice stream is mandatory and        arbitrated by the PoC server. The video stream is optional and        not arbitrated by the PoC server.    -   Video Push-to-Talk with video that follows the talker. In this        service, video is transmitted by a current talker to the other        participating MSs. In this service, the voice stream is        mandatory and arbitrated by the PoC server. The video stream is        optional and arbitrated by the PoC server.    -   Push-to-Talk with non-arbitrated video, where users can        independently select a video feed from another participant in        the same SIP session. This service includes a mandatory voice        stream that is arbitrated by the PoC server and an optional        non-arbitrated video stream.    -   Push-to-Jam, where one user is transmitting a music stream,        while another user is, for instance, talking or singing. This        service includes a PoC server arbitrated voice stream and a        client arbitrated music stream.    -   Push-to-Lecture, where, for instance, a professor giving a        lecture, decides the floor should be granted to a student for a        question. In this service, the voice stream is mandatory and PoC        server arbitrated and the video stream is optional and user        arbitrated.    -   Push-to-Track, where one user is transmitting real-time location        information (e.g., first responder at incident location), and        other users have arbitrated voice. In this service, the voice        stream is mandatory and PoC server arbitrated and a positioning        stream is also mandatory, but user arbitrated.    -   Video Customer Service, where a customer service organization        determines whether the organization or the customer is sharing a        video. In this service, the voice stream is mandatory and PoC        server arbitrated and the video stream is optional and user        arbitrated.

FIG. 7 is a Push-To-Talk (PTT) communications session processing flowdiagram 700 according to yet another embodiment of the presentinvention. Processing flow 700 is performed by exemplary embodiments ofthe present invention to establish and maintain a PoC communicationsession where arbitration can be shared. Processing flow 700 begins byestablishing, at step 702, a Push-To-Talk (PTT) communication sessionbetween two or more UEs, for example, two or more of MSs 106-108 orother suitably equipped communications devices such as wiredcommunication device 112. In this exemplary embodiment, the two or moreUEs communicate through a SIP Push-To-Talk (PTT) server, such as PoCserver 110, which retains arbitration over voice streams. At step 704,one of the participating UEs, for example, MS 106, notifies at least oneother participating UE, for example, MS 107, that it wishes to send amedia stream to the other UE. At step 706, the notifying UE, that is, MS106, begins transmitting its media file in the form of a stream, butinstead of sending it to the PoC server 110 and allowing the PoC serverto arbitrate which devices receive the stream, the sending UE, that is,MS 106, acts as the arbiter and sends the stream to the appropriateparticipating UEs bypassing the PoC server 110 and without receiving atransmit instruction from the PoC server. At step 708, once the completemedia stream is sent or the sending UE, that is, MS 106, endstransmission, as in the case of a video stream with no ending, forexample, a surveillance camera, at step 710 the sending UE ceasesarbitrating and the communication session continues with the PoC server110 arbitrating voice transmission. The processing flow diagram 700 thenends.

The present invention may be realized in hardware, software, or acombination of hardware and software. A system according to an exemplaryembodiment of the present invention may be realized in a centralizedfashion in one computer system, or in a distributed fashion wheredifferent elements are spread across several interconnected computersystems. Any kind of computer system—or other apparatus adapted forcarrying out the methods described herein—is suited. A typicalcombination of hardware and software might be a general purpose computersystem with a computer program that, when being loaded and executed,controls the computer system in order to carry out the methods describedherein.

The present invention may also be embedded in a computer programproduct, which comprises all the features enabling the implementation ofthe methods described herein, and which—when loaded in a computersystem—is able to carry out these methods. Computer program means orcomputer program in the present context mean any expression, in anylanguage, code or notation, of a set of instructions intended to cause asystem having an information processing capability to perform aparticular function either directly or after either or both of thefollowing a) conversion to another language, code or, notation; and b)reproduction in a different material form.

Each computer system may include, inter alia, one or more computers andat least one computer readable medium that allows the computer to readdata, instructions, messages or message packets, and other computerreadable information. The computer readable medium may includenon-volatile memory, such as ROM, Flash memory, Disk drive memory,CD-ROM, SIM card, and other permanent storage. Additionally, a computermedium may include, for example, volatile storage such as RAM, buffers,cache memory, and network circuits.

The terms program, software application, and the like as used herein,are defined as a sequence of instructions designed for execution on acomputer system. A program, computer program, or software applicationmay include a subroutine, a function, a procedure, an object method, anobject implementation, an executable application, an applet, a servlet,a source code, an object code, a shared library/dynamic load libraryand/or other sequence of instructions designed for execution on acomputer system.

Reference throughout the specification to “one embodiment” means that aparticular feature, structure, or characteristic described in connectionwith the embodiment is included in at least one embodiment of thepresent invention. Thus, the appearances of the phrases “in oneembodiment” in various places throughout the specification are notnecessarily all referring to the same embodiment. Furthermore, theparticular features, structures, or characteristics may be combined inany suitable manner in one or more embodiments. Moreover theseembodiments are only examples of the many advantageous uses of theinnovative teaching herein. In general, statements made in thespecification of the present application do not necessarily limit any ofthe various claimed inventions. Moreover, some statements may apply tosome inventive features but not to others. In general, unless otherwiseindicated, singular elements may be in the plural and visa versa with noloss of generality.

While the various embodiments of the invention have been illustrated anddescribed, it will be clear that the invention is not so limited.Numerous modifications, changes, variations, substitutions andequivalents will occur to those skilled in the art without departingfrom the spirit and scope of the present invention as defined by theappended claims.

1. A method of managing a Push-To-Talk over Cellular communicationsession comprising a media stream, the method comprising: engaging, by auser equipment, in a Session Initiation Protocol Push-To-Talkcommunication session that includes a Session Initiation ProtocolPush-To-Talk server and at least one other user equipment; anddesignating, by the user equipment, one of the Session InitiationProtocol Push-To-Talk server, the user equipment, and the at least oneother user equipment to act as an arbiter of the media stream, whereinthe arbiter grants a floor for transmitting the media stream.
 2. Themethod of claim 1, wherein the user equipment is an originator of theSession Initiation Protocol Push-To-Talk communication session.
 3. Themethod of claim 2, wherein designating comprises designating, by theuser equipment and when establishing the communication session, one ofthe Session Initiation Protocol Push-To-Talk server to act as an arbiterof the media stream, the user equipment to act as an arbiter of themedia stream, and the at least one other user equipment to act as anarbiter of the media stream.
 4. The method of claim 1, furthercomprising, prior to designating, requesting, by the user equipment, toadd the media stream to the Session Initiation Protocol Push-To-Talkcommunication session.
 5. The method of claim 4, wherein the userequipment is not an originator of the Session Initiation ProtocolPush-To-Talk communication session.
 6. The method according to claim 4,wherein the user equipment designates one of the Session InitiationProtocol Push-To-Talk server to act as an arbiter of the media stream,the user equipment to act as an arbiter of the media stream, and the atleast one other user equipment to act as an arbiter of the media stream.7. The method of claim 1, further comprising receiving, by the userequipment, the media stream.
 8. The method of claim 1, furthercomprising transmitting, by the user equipment and while engaged in thecommunication session, the media stream to the at least one other userequipment without receiving a transmit instruction from the Push-To-Talkserver.
 9. The method according to claim 1, further comprisingreceiving, by the user equipment and while engaged in the SessionInitiation Protocol Push-To-Talk communication session, the media streamfrom the at least one other user equipment without a conveyance of atransmit instruction by the Push-To-Talk server to the at least oneother user equipment.
 10. The method according to claim 1, whereindesignating comprises designating, by the user equipment, the userequipment to act as an arbiter of the media stream wherein the methodfurther comprises: receiving, by the designated arbiter, a request totransmit; and in response to receiving the request to transmit,conveying, by the by the designated arbiter, a floor grant.
 11. Themethod according to claim 1, further comprising: conveying, by aparticipant in the Session Initiation Protocol Push-To-Talkcommunication session to the designated arbiter, a request to transmit;in response to conveying the request to transmit, receiving, by theparticipant from the designated arbiter, a floor grant; replicating, bythe participant, the media stream to produce a plurality of replicatedcopies of the media stream; and conveying, by the by the participant,the plurality of replicated copies of the media stream to otherparticipants in the communication session.
 12. The method according toclaim 1, further comprising: receiving, by the designated arbiter, themedia stream; replicating, by the designated arbiter, the media streamto produce a plurality of replicated copies of the media stream; andconveying, by the by the designated arbiter, the plurality of replicatedcopies of the media stream to other participants in the communicationsession.
 13. The method of claim 1, wherein the Session InitiationProtocol Push-To-Talk communication session comprises a plurality ofmedia streams and wherein the user equipment designates an arbiter foreach media stream of the plurality of media streams.
 14. The method ofclaim 1, wherein the Session Initiation Protocol Push-To-Talkcommunication session comprises a plurality of media streams and whereinthe user equipment designates a different arbiter for each media streamof the plurality of media streams.
 15. The method of claim 1, whereindesignating comprises designating, by the user equipment, the at leastone other user equipment to act as an arbiter of the media stream andfurther comprising designating, by the at least one other userequipment, one or more of the Session Initiation Protocol Push-To-Talkserver to act as an arbiter of the media stream, the user equipment toact as an arbiter of the media stream, and yet another user equipment toact as an arbiter of the media stream.
 16. The method of claim 1,wherein the Session Initiation Protocol Push-To-Talk communicationsession comprises a plurality of media streams, wherein a first mediastream of the plurality of media streams has a different originator thana second media stream of the plurality of media streams, and wherein anoriginator of the first media stream designates an arbiter of the firstmedia stream and an originator of the second media stream designates anarbiter of the second stream.
 17. The method according to claim 1,wherein the communication session comprises a plurality of media streamsand wherein the method further comprises: designating one or more mediastreams of the plurality of media streams as mandatory; and performingone of: sending an instruction to remove from the session all of the atleast one second user equipment that does not have media playbackability with respect to the mandatory media stream; disallowing thesession if any of the at least one second user equipment does not havemedia playback ability with respect to the mandatory media stream; anddisallowing all of the at least one second user equipment that does nothave media playback ability with respect to the mandatory media streamfrom receiving the mandatory media streams.
 18. The method according toclaim 1, further comprising designating the media stream as optional.19. The method according to claim 18, further comprising, when the mediastream is designated as optional, allowing user equipment that havemedia playback ability to choose whether to receive the media stream.20. A user equipment comprising a processor that is adapted to:designate, while engaged in a Session Initiation Protocol Push-To-Talkcommunication session that includes a media stream, a Session InitiationProtocol Push-To-Talk server, and at least one other user equipment, atleast one of a Session Initiation Protocol Push-To-Talk server and oneof the at least one other user equipment to act as an arbiter of a mediastream, wherein the arbiter grants a floor for transmitting the mediastream; and transmit, while engaged in the communication session andwithout receiving a transmit instruction from the Push-To-Talk server,the media stream directly to at least one of the at least one other userequipment.
 21. The user equipment according to claim 20, wherein thecommunication session comprises a plurality of media streams and whereinthe first user equipment requests an arbiter for each media stream ofthe plurality of media streams.
 22. The user equipment according toclaim 20, wherein the communication session comprises a plurality ofmedia streams and wherein the first user equipment requests a differentarbiter for each media stream of the plurality of media streams.
 23. Theuser equipment according to claim 20, wherein the communication sessioncomprises a plurality of media streams, wherein a first media stream ofthe plurality of media streams has a different originator than a secondmedia stream of the plurality of media streams, and wherein anoriginator of the first media stream designates an arbiter of the firstmedia stream and an originator of the second media stream designates anarbiter of the second stream.
 24. The user equipment according to claim20, further comprising a transceiver for receiving a grant, from thearbiter of a floor with respect to a media stream, and wherein thetransmitting is in response to the grant.
 25. The user equipmentaccording to claim 20, wherein the processor further is adapted todesignate a media stream as mandatory.
 26. The user equipment of claim20, wherein the communication session comprises a plurality of mediastreams, wherein a media stream of the plurality of media streams isdesignated as mandatory, and wherein the processor is adapted to performone of: send an instruction to remove from the session all of the atleast one other user equipment that does not have media playback abilitywith respect to the mandatory media stream; disallow the session if anyof the at least one other user equipment does not have media playbackability with respect to the mandatory media stream; and disallow all ofthe at least one other user equipment that does not have media playbackability from receiving the mandatory media stream.
 27. The userequipment according to claim 20, wherein the processor is adapted todesignate the media stream as optional.